Working around the front or the back of a post of the previous row gives an interesting raised ridge on the crochet fabric. Around-the-post crochet is worked by inserting the hook from the front or back and around the post of the crochet stitch of the previous row. While this technique is commonly worked...

*Yarn over 2 times, insert hook in stitch, yarn over and pull up loop (4 loops on hook; Figure 1), yarn over and draw through 2 loops (Figure 2), yarn over and draw through 2 loops, yarn over and draw through remaining 2 loops (Figure 3); repeat from *.